New study reveals abnormal thalamocortical connectivity in autism

Individuals with autism spectrum disorder (ASD) exhibit differences in basic sensorimotor processing as well as general cortical excitability. These observations converge to implicate thalamocortical connectivity as a potential unifying neural mechanism. In collaboration with Dr. Carissa Cascio, the Woodward Lab used resting-state fMRI data from the Autism Brain Imaging Data Exchange to investigate thalamocortical functional connectivity in 228 individuals with ASD and a matched comparison group of 228 typically developing individuals. The results of this study revealed increased functional connectivity between the cortex and thalamus in ASD. Abnormal connectivity tended to converge in temporal cortical areas, including the temporoparietal junction. Follow-up analyses of age effects revealed that functional hyper-connectivity in individuals with ASD is more pronounced in adolescents compared with children and adults. These results confirm previous findings of temporal and motor thalamocortical hyperconnectivity in ASD and extend them to include somatosensory and prefrontal cortices. This widespread hyperconnectivity could theoretically account for sensorimotor symptoms and general cortical excitability in ASD.